/*

Alan Fortes 
cpe301

The following c code runs on the ATmega328p,
which receives data from an accelerometer,
processes that data to output the posture of
an individual, the angle at which the person
is leaning forward, and the rate and intensity
of that person's movement.

This data is transmitted via a Bluetooth unit
to a Bluetooth compatible computer. This data
is plotted onto a graph.

*/


#define F_CPU 8000000
#include <inttypes.h>
#include <stdint.h>
#include <avr/io.h>
#include <util/delay.h>
#include <util/twi.h>
#include <avr/interrupt.h>
#include <math.h>
#include <stdio.h>


#define MPU6050_ADDRESS 0b11010000 // Address with end write bit
#define MPU6050_RA_XG_OFFS_TC 0x00 //[7] PWR_MODE, [6:1] XG_OFFS_TC, [0] OTP_BNK_VLD
#define MPU6050_RA_YG_OFFS_TC 0x01 //[7] PWR_MODE, [6:1] YG_OFFS_TC, [0] OTP_BNK_VLD
#define MPU6050_RA_ZG_OFFS_TC 0x02 //[7] PWR_MODE, [6:1] ZG_OFFS_TC, [0] OTP_BNK_VLD
#define MPU6050_RA_X_FINE_GAIN 0x03 //[7:0] X_FINE_GAIN
#define MPU6050_RA_Y_FINE_GAIN 0x04 //[7:0] Y_FINE_GAIN
#define MPU6050_RA_Z_FINE_GAIN 0x05 //[7:0] Z_FINE_GAIN
#define MPU6050_RA_XA_OFFS_H 0x06 //[15:0] XA_OFFS
#define MPU6050_RA_XA_OFFS_L_TC 0x07
#define MPU6050_RA_YA_OFFS_H 0x08 //[15:0] YA_OFFS
#define MPU6050_RA_YA_OFFS_L_TC 0x09
#define MPU6050_RA_ZA_OFFS_H 0x0A //[15:0] ZA_OFFS
#define MPU6050_RA_ZA_OFFS_L_TC 0x0B
#define MPU6050_RA_XG_OFFS_USRH 0x13 //[15:0] XG_OFFS_USR
#define MPU6050_RA_XG_OFFS_USRL 0x14
#define MPU6050_RA_YG_OFFS_USRH 0x15 //[15:0] YG_OFFS_USR
#define MPU6050_RA_YG_OFFS_USRL 0x16
#define MPU6050_RA_ZG_OFFS_USRH 0x17 //[15:0] ZG_OFFS_USR
#define MPU6050_RA_ZG_OFFS_USRL 0x18
#define MPU6050_RA_SMPLRT_DIV 0x19
#define MPU6050_RA_CONFIG 0x1A
#define MPU6050_RA_GYRO_CONFIG 0x1B
#define MPU6050_RA_ACCEL_CONFIG 0x1C
#define MPU6050_RA_FF_THR 0x1D
#define MPU6050_RA_FF_DUR 0x1E
#define MPU6050_RA_MOT_THR 0x1F
#define MPU6050_RA_MOT_DUR 0x20
#define MPU6050_RA_ZRMOT_THR 0x21
#define MPU6050_RA_ZRMOT_DUR 0x22
#define MPU6050_RA_FIFO_EN 0x23
#define MPU6050_RA_I2C_MST_CTRL 0x24
#define MPU6050_RA_I2C_SLV0_ADDR 0x25
#define MPU6050_RA_I2C_SLV0_REG 0x26
#define MPU6050_RA_I2C_SLV0_CTRL 0x27
#define MPU6050_RA_I2C_SLV1_ADDR 0x28
#define MPU6050_RA_I2C_SLV1_REG 0x29
#define MPU6050_RA_I2C_SLV1_CTRL 0x2A
#define MPU6050_RA_I2C_SLV2_ADDR 0x2B
#define MPU6050_RA_I2C_SLV2_REG 0x2C
#define MPU6050_RA_I2C_SLV2_CTRL 0x2D
#define MPU6050_RA_I2C_SLV3_ADDR 0x2E
#define MPU6050_RA_I2C_SLV3_REG 0x2F
#define MPU6050_RA_I2C_SLV3_CTRL 0x30
#define MPU6050_RA_I2C_SLV4_ADDR 0x31
#define MPU6050_RA_I2C_SLV4_REG 0x32
#define MPU6050_RA_I2C_SLV4_DO 0x33
#define MPU6050_RA_I2C_SLV4_CTRL 0x34
#define MPU6050_RA_I2C_SLV4_DI 0x35
#define MPU6050_RA_I2C_MST_STATUS 0x36
#define MPU6050_RA_INT_PIN_CFG 0x37
#define MPU6050_RA_INT_ENABLE 0x38
#define MPU6050_RA_DMP_INT_STATUS 0x39
#define MPU6050_RA_INT_STATUS 0x3A
#define MPU6050_RA_ACCEL_XOUT_H 0x3B
#define MPU6050_RA_ACCEL_XOUT_L 0x3C
#define MPU6050_RA_ACCEL_YOUT_H 0x3D
#define MPU6050_RA_ACCEL_YOUT_L 0x3E
#define MPU6050_RA_ACCEL_ZOUT_H 0x3F
#define MPU6050_RA_ACCEL_ZOUT_L 0x40
#define MPU6050_RA_TEMP_OUT_H 0x41
#define MPU6050_RA_TEMP_OUT_L 0x42
#define MPU6050_RA_GYRO_XOUT_H 0x43
#define MPU6050_RA_GYRO_XOUT_L 0x44
#define MPU6050_RA_GYRO_YOUT_H 0x45
#define MPU6050_RA_GYRO_YOUT_L 0x46
#define MPU6050_RA_GYRO_ZOUT_H 0x47
#define MPU6050_RA_GYRO_ZOUT_L 0x48
#define MPU6050_RA_EXT_SENS_DATA_00 0x49
#define MPU6050_RA_EXT_SENS_DATA_01 0x4A
#define MPU6050_RA_EXT_SENS_DATA_02 0x4B
#define MPU6050_RA_EXT_SENS_DATA_03 0x4C
#define MPU6050_RA_EXT_SENS_DATA_04 0x4D
#define MPU6050_RA_EXT_SENS_DATA_05 0x4E
#define MPU6050_RA_EXT_SENS_DATA_06 0x4F
#define MPU6050_RA_EXT_SENS_DATA_07 0x50
#define MPU6050_RA_EXT_SENS_DATA_08 0x51
#define MPU6050_RA_EXT_SENS_DATA_09 0x52
#define MPU6050_RA_EXT_SENS_DATA_10 0x53
#define MPU6050_RA_EXT_SENS_DATA_11 0x54
#define MPU6050_RA_EXT_SENS_DATA_12 0x55
#define MPU6050_RA_EXT_SENS_DATA_13 0x56
#define MPU6050_RA_EXT_SENS_DATA_14 0x57
#define MPU6050_RA_EXT_SENS_DATA_15 0x58
#define MPU6050_RA_EXT_SENS_DATA_16 0x59
#define MPU6050_RA_EXT_SENS_DATA_17 0x5A
#define MPU6050_RA_EXT_SENS_DATA_18 0x5B
#define MPU6050_RA_EXT_SENS_DATA_19 0x5C
#define MPU6050_RA_EXT_SENS_DATA_20 0x5D
#define MPU6050_RA_EXT_SENS_DATA_21 0x5E
#define MPU6050_RA_EXT_SENS_DATA_22 0x5F
#define MPU6050_RA_EXT_SENS_DATA_23 0x60
#define MPU6050_RA_MOT_DETECT_STATUS 0x61
#define MPU6050_RA_I2C_SLV0_DO 0x63
#define MPU6050_RA_I2C_SLV1_DO 0x64
#define MPU6050_RA_I2C_SLV2_DO 0x65
#define MPU6050_RA_I2C_SLV3_DO 0x66
#define MPU6050_RA_I2C_MST_DELAY_CTRL 0x67
#define MPU6050_RA_SIGNAL_PATH_RESET 0x68
#define MPU6050_RA_MOT_DETECT_CTRL 0x69
#define MPU6050_RA_USER_CTRL 0x6A
#define MPU6050_RA_PWR_MGMT_1 0x6B
#define MPU6050_RA_PWR_MGMT_2 0x6C
#define MPU6050_RA_BANK_SEL 0x6D
#define MPU6050_RA_MEM_START_ADDR 0x6E
#define MPU6050_RA_MEM_R_W 0x6F
#define MPU6050_RA_DMP_CFG_1 0x70
#define MPU6050_RA_DMP_CFG_2 0x71
#define MPU6050_RA_FIFO_COUNTH 0x72
#define MPU6050_RA_FIFO_COUNTL 0x73
#define MPU6050_RA_FIFO_R_W 0x74
#define MPU6050_RA_WHO_AM_I 0x75
#define SCL_CLOCK  200000
#define I2C_READ    1
#define I2C_WRITE    0
int16_t accel_buff[3], gyro_buff[3];

void printStringToScreen(char *sentence){
	
	while ((*sentence !='\0')){ // While the end of the sentence hasn't been reached
		// the output string will be displayed, character by character.
		
		while(!(UCSR0A&(1<<UDRE0)));
		
		UDR0 = *sentence;
		
		sentence++; // The position of next character of the output string is gotten.
	}
	
}

void i2c_stop(){
	char outputString2[999];
	TWCR = (1<<TWINT)|(1<<TWEN)|(1<TWSTO);	
	snprintf(outputString2,sizeof(outputString2), "Stop sequence set: %3x\r\n\n", TWSR);
	printStringToScreen(outputString2);
	_delay_ms(1500);
}

//***********************************************************
void i2c_start(unsigned char address)
{
	char outputString2[999];
	
	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);

	while(!(TWCR & (1<<TWINT)));
	
	snprintf(outputString2,sizeof(outputString2), "Start sequence for MPU initialization: %3x\r\n\n", TWSR);
	printStringToScreen(outputString2);
	_delay_ms(1500);
	
	// check value of TWI Status Register. Mask prescaler bits.
	TWDR = address;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	snprintf(outputString2,sizeof(outputString2), "MPU device write address set: %3x\r\n\n", TWSR);
	printStringToScreen(outputString2);
	_delay_ms(1500);

	}/* i2c_start */

//***********************************************************


void i2c_write( unsigned char data )
{

	char outputString2[999];
	// send data to the previously addressed device
	TWDR = data;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));

	snprintf(outputString2,sizeof(outputString2), "MPU register/data written: %3x\r\n\n", TWSR);
	printStringToScreen(outputString2);
	_delay_ms(1500);

	}/* i2c_write */	
	
void i2c_write_byte(uint8_t dev_addr, uint8_t reg_addr, uint8_t data){
	
	i2c_start(dev_addr+I2C_WRITE);
	i2c_write(reg_addr);
	i2c_write(data);
	i2c_stop();

}

void mpu6050_init(void){
	
	i2c_write_byte(MPU6050_ADDRESS, MPU6050_RA_PWR_MGMT_1, 0x00); //exit sleep mode
	i2c_write_byte(MPU6050_ADDRESS, MPU6050_RA_CONFIG, 0x00); // LPF, bandwidth = 184(accel) and 188(gyro)
	i2c_write_byte(MPU6050_ADDRESS, MPU6050_RA_GYRO_CONFIG, 0x00); // gyro ADC scale: 1000 deg/s
	i2c_write_byte(MPU6050_ADDRESS, MPU6050_RA_ACCEL_CONFIG, 0x00); //accel ADC scale: 2 g
	i2c_write_byte(MPU6050_ADDRESS, MPU6050_RA_INT_ENABLE, 0x00); //enable data ready interrupt
	i2c_write_byte(MPU6050_ADDRESS, MPU6050_RA_SIGNAL_PATH_RESET, 0x00); //don't reset signal path

}



 

//***********************************************************


//***********************************************************




void i2c_start_wait(unsigned char address){
		 
		TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		TWDR = address;
		TWCR = (1<<TWINT) | (1<<TWEN);
		char outputString2[999];
		snprintf(outputString2,sizeof(outputString2), "X gyro value :%3x\r\n\n", TWSR);
		printStringToScreen(outputString2);
		_delay_ms(500);
	
		
	

	}/* i2c_start_wait */

void i2c_clock_init(void){
	
	TWSR = 0;
	//set prescaler bits to 0
	TWBR = 32;
}

void uart_init(){
	
	DDRD = 0xFF;
	ADCSRA = 0x82;
	ADMUX = 0x00;
	UCSR0B = 0x08;
	UCSR0C = 0x06;
	UBRR0 = 0x0033;
}


void wakeup(void){
	
TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), "Getting device out of sleep mode\r\n\n");
//printStringToScreen(outputString);
_delay_ms(500);

// Write sequence: MPU6050 address

TWDR = 0xD0;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), " ");
//printStringToScreen(outputString);
//_delay_ms(1500);

// Accessing desired register
//y++;// y = 3
TWDR = MPU6050_RA_PWR_MGMT_1;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString)," ");
//printStringToScreen(outputString);
//_delay_ms(1500);

TWDR = 0;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString)," ");
//printStringToScreen(outputString);
}

void initialize(void){

TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), "module initialization\r\n\n");
//printStringToScreen(outputString);
_delay_ms(500);

// Write sequence: MPU6050 address

TWDR = 0xD0;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), " ");
//printStringToScreen(outputString);
//_delay_ms(1500);

// Accessing desired register

TWDR = MPU6050_RA_CONFIG;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString)," ");
//printStringToScreen(outputString);
//_delay_ms(1500);

TWDR = 1;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString)," ");
//printStringToScreen(outputString);
//_delay_ms(1500);





}



void initializeAccel(void){

	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), "module initialization\r\n\n");
	//printStringToScreen(outputString);
	_delay_ms(500);

	// Write sequence: MPU6050 address

	TWDR = 0xD0;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	//_delay_ms(1500);

	// Accessing desired register

	TWDR = MPU6050_RA_ACCEL_CONFIG;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString)," ");
	//printStringToScreen(outputString);
	//_delay_ms(1500);

	TWDR = 0;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString)," ");
	//printStringToScreen(outputString);
	//_delay_ms(1500);
	TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
	///////////////////////

	/********************************************************************/
	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), "Getting device out of sleep mode\r\n\n");
	//printStringToScreen(outputString);
	_delay_ms(500);

}

void initializeGyro(void){

TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), "module initialization\r\n\n");
//printStringToScreen(outputString);
_delay_ms(500);

// Write sequence: MPU6050 address

TWDR = 0xD0;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), " ");
//printStringToScreen(outputString);
//_delay_ms(1500);

// Accessing desired register

TWDR = MPU6050_RA_CONFIG;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString)," ");
//printStringToScreen(outputString);
//_delay_ms(1500);

TWDR = 1<<4;
TWCR = (1<<TWINT) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString)," ");
//printStringToScreen(outputString);
//_delay_ms(1500);
TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
///////////////////////

/********************************************************************/
TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
while(!(TWCR & (1<<TWINT)));
//snprintf(outputString,sizeof(outputString), "Getting device out of sleep mode\r\n\n");
//printStringToScreen(outputString);	

}


int getX(void){
	
	char outputString[999];
	int16_t x;
	uint8_t tmp[2];
	int y = 0;
	
		y++; // y = 1
		TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		//snprintf(outputString,sizeof(outputString), " ");
		//printStringToScreen(outputString);
		_delay_ms(10);
		
		// Write sequence: MPU6050 address
		y++;// y = 2
		TWDR = 0xD0;
		TWCR = (1<<TWINT) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		//snprintf(outputString,sizeof(outputString), " ");
		//printStringToScreen(outputString);
		_delay_ms(10);
		
		// Accessing desired register
		y++;// y = 3
		TWDR = 0x3c;
		TWCR = (1<<TWINT) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		//snprintf(outputString,sizeof(outputString)," ");
		//printStringToScreen(outputString);
		_delay_ms(10);
		
		// Stop writing
		y++;// y = 4
		TWCR = (1<<TWINT)|(1<<TWEN)|(1<TWSTO);
		
		//snprintf(outputString,sizeof(outputString), " ");
		//printStringToScreen(outputString);
		_delay_ms(10);
		
		// Read Start sequence
		y++;// y = 5
		TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		//snprintf(outputString,sizeof(outputString), " ");
		//printStringToScreen(outputString);
		_delay_ms(10);
		
		// Read sequence: MPU6050 address
		y++;//y = 6
		TWDR = 0xD1;
		TWCR = (1<<TWINT) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		//snprintf(outputString,sizeof(outputString), " ");
		//printStringToScreen(outputString);
		_delay_ms(10);
		
		// Read sequence: MPU6050 address
		y++;//7
		TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
		while(!(TWCR & (1<<TWINT)));
		snprintf(outputString,sizeof(outputString), " ");
		printStringToScreen(outputString);
		//_delay_ms(1500);
		tmp[0] = TWDR;
		
		TWCR = (1<<TWINT) | (1<<TWEN);
		while(!(TWCR & (1<<TWINT)));
		//snprintf(outputString,sizeof(outputString), " ");
		//printStringToScreen(outputString);
		//_delay_ms(1500);
		tmp[1] = TWDR;
		
		
		x = (tmp[0]<<8)|(tmp[1]);
		
		TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
		return x;
		// Read sequence: MPU6050 address

		_delay_ms(10);
	
	
}

int getY(void){
	
	char outputString[999];
	int16_t x;
	uint8_t tmp[2];
	int y = 0;
	
	y++; // y = 1
	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	_delay_ms(10);
	
	// Write sequence: MPU6050 address
	y++;// y = 2
	TWDR = 0xD0;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	_delay_ms(10);
	
	// Accessing desired register
	y++;// y = 3
	TWDR = 0x3e;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString)," ");
	//printStringToScreen(outputString);
	_delay_ms(10);
	
	// Stop writing
	y++;// y = 4
	TWCR = (1<<TWINT)|(1<<TWEN)|(1<TWSTO);
	
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	_delay_ms(10);
	
	// Read Start sequence
	y++;// y = 5
	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	_delay_ms(10);
	
	// Read sequence: MPU6050 address
	y++;//y = 6
	TWDR = 0xD1;
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	_delay_ms(10);
	
	// Read sequence: MPU6050 address
	y++;//7
	TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
	while(!(TWCR & (1<<TWINT)));
	snprintf(outputString,sizeof(outputString), " ");
	printStringToScreen(outputString);
	//_delay_ms(1500);
	tmp[0] = TWDR;
	
	TWCR = (1<<TWINT) | (1<<TWEN);
	while(!(TWCR & (1<<TWINT)));
	//snprintf(outputString,sizeof(outputString), " ");
	//printStringToScreen(outputString);
	//_delay_ms(1500);
	tmp[1] = TWDR;
	
	
	x = (tmp[0]<<8)|(tmp[1]);
	
	TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
	return x;
	// Read sequence: MPU6050 address

	_delay_ms(10);
}

int main(void){

	char outputString[999];
	int x;
	int y;
	int currentX = 0;
	int differenceX;
	int newX = 0;
	int Y1 = 0; 
	int Y2 = 0; 
	int differenceY = 0;
	uart_init();
	
	//The device is put through the proper steps for
	//getting out of sleep mode and initialization.
	wakeup();
	initialize();
	initializeGyro();
	initializeAccel();

	
	while(1){
	
	x =	getX(); //The value of the x axis accelerometer is obtained.
	y =	getY();	//The value of the y axis accelerometer is obtained.		
		
	newX = x; //The latest value of x is loaded to a variable that 
	          //will be compared to the previous value of x to see
			  //if the threshold has been surpassed.
	
	Y2 = Y1;  //What was the previous value of y is stored as Y2.
	
	Y1 = y;  //The value of Y1 is updated to be y.
	
	
	 newX /= 185.177777;
	 //Only if the value of the 
	 differenceX = newX - currentX; 
		if((differenceX >= 3) || (differenceX <= -3)){ //To ensure that errant changes in voltage do not
			//make the servo motor twitch, the change must be
			currentX = newX;                              //great enough to be acknowledged.
			
		}
	 
	 //If the magnitude of differences of Y1 and Y2 are high enough,
	 //then it will be registered. The absolute value is taken, so 
	 //that it can be displayed only as rising spikes on screen.
	 if(((Y1 - Y2) >= 200) || ((Y1 - Y2) <= -200)){ 
		
		differenceY = Y1 - Y2;
		 
	 }else{
		 
		differenceY = 0;
	 }
	 
	 if(differenceY < 0){
		 
		 differenceY *= -1;
		 
		 
	 }
	 
	 //This if statement is a cutoff mark for values that are too 
	 //hight for the graph.
	 if(differenceY > 15000){
		 
		 differenceY = 12000;
		 
		 
	 }
		snprintf(outputString,sizeof(outputString), "%3d, %3d\r\n\n", currentX + 90, differenceY);
		printStringToScreen(outputString);
	
	
	}
	


}